Pumps for moving fluids are well known in the art. Such pumps may be of an in-line nature such that the pump pumps fluids through it. There are a variety of devices which are used to control the activation and de-activation of such pumps. As one of ordinary skill in the art can appreciate, the continued running of a fluid pump when there is no fluid to pump, i.e., running the pump dry, can be harmful to the life of the pump. In addition, the continued running of a fluid pump when there is a substantial downstream restriction is also harmful to the life of a pump. This is the case where a pump to attached to line which terminates at a closed faucet, for example. As such, it is desirable to have a pump controller device which can de-activate the running of a pump when the fluid circuit enters either one of these undesirable conditions. In addition, it is recognized that some prior art controller devices unnecessarily cycle the pump into on and off conditions. Such unnecessary on/off cycling is undesirable are this too is harmful to the life of the pump. There is known in the art pump controller devices which have attempted to guard some of these conditions. These prior art pump controller devices, however, are typically complex and may include a variety of electronic senors and actuators. Such complexity often impacts the manufacturing and maintenance costs, reliability and relative ease of use.
It is therefore evident that there exists a need in the art for a pump controller facilitates de-activation of a pump under multiple conditions and which is relatively simple in construction and use.